How to set a specific color on an attribute or group

[anbt]

Hello,

I am just starting with Redshift within Houdini and I have gone through the basics.
I have a sim that I exported as an alembic and I used the unpackSOP to recover my point attributes and prim groups, all on the same mesh.

How would I go about applying a different colour or texture on those groups.
How can I use the point attribute to drive a particular color?

Thanks a lot

[Sepu]

The material SOP allows you to apply different materials to different groups.
The user_color_data or point_Attribute allows you to use attributes to materials such as Cd, etc. 

[anbt]

Thanks @Sepu 

[anbt]

hey @Sepu, any idea what is wrong in here?
I applied a material per group after unpacking. But the render view is completely blank. It isn't coming from the light.

Cheers



and this is how the alembic was done, maybe I've done something wrong in here

Edited February 3, 2021 by anbt

[nicolas.schlafer]

Not sure from where is your problem coming, but is it a specific reason for which you are passing by an alembic and not only a .bgeo.sc cache that you merge in your other network or import in your other project?

[anbt]

@nicolas.schlafer I was looking at this https://www.sidefx.com/docs/houdini/render/tips.html and tought alembic was the way to go for efficiency. I can see my sim plays in realtime from the alembic. From the file cache it doesn't.

I tried again from the file cache, but I still have the same problem

Edited February 3, 2021 by anbt

[nicolas.schlafer]

@anbt I am not expert neither but from what i understand, the alembic play smoother because it's packed geometry, but you could pack your scene before a file cache too. I always thought alembic was primarily useful for data exchange between different DCC.

Maybe i am wrong here and there is some optimisation of ABC files over standard packed file cache, would be interesting to have other inputs on this.

[anbt]

now it is working, no idea why. I didn't change anything from the screenshot above....
I did restart Houdini half an Hour ago but idk, weeiiiirrdd!

I finally know about putting a different texture on each group, now I will try figuring out how to apply a texture controlled by an attribute.
I have this stress float attribute that I want to colourise, a bit like you can visualise it in the DOPnet or Vellum Solver..
Will start by checking out what Sepu posted with this "user_color_data or point_Attribute"

Edited February 3, 2021 by anbt